Cleaning agent composition

ABSTRACT

The present invention provides a cleanser composition having a high foaming ability with a low stimulus to the skin. The cleanser composition of the present invention is weakly acidic and comprises (a) a phosphate monoester represented by the general formula (1) and (b) a phosphate diester represented by the general formula (2) wherein the ratio of the component (a) to the component (b), i.e. the (a)/(b) ratio, is from 65/35 to 90/10 by weight:  
                 
 
wherein R 1  represents an alkyl or alkenyl group containing 9 to 15 carbon atoms on average with a branching degree of 10% or more, X 1  and X 2  and X 3  each represent a hydrogen atom or an alkali metal, and n is a number of 0 to 5.

TECHNICAL FIELD

The present invention relates to a cleanser composition having a highfoaming ability with a low stimulus to the skin.

BACKGROUND ART

Conventionally, anionic surfactants such as higher fatty acid salts,alkyl sulfates, polyoxyethylene alkyl sulfates, alkyl benzenesulfonates, and α-olefin sulfonates have been widely used as cleanserfor washing the skin. However, when cleanser containing such anionicsurfactants are used, there is a tendency to cause skin damages such aschaps on the hand.

On the other hand, nonionic surfactants are known to hardly causechapped skin, but are inferior to the anionic surfactants in fundamentalperformance as a cleanser, such as foaming ability and detergency.

As one kind of anionic surfactant, a phosphate-based surfactant is knownas a mild surfactant with a low stimulus to the skin. This surfactant isproduced, for example, by reacting a fatty alcohol with aphosphorylating agent such as phosphoric anhydride or phosphorusoxychloride, and the reaction product is obtained usually as a mixtureof monoesters and diesters or a mixture of mono-, di- and triesters.Particularly, when the resulting alkyl esters contain a higher contentof diesters and triesters with a high content of linear chains, they areinferior in solubility in water and foaming ability, and thus the purityof the monoesters should be increased through a troublesome purificationprocess.

On the other hand, a phosphate compound having an oxyethylene groupintroduced into it for improving water solubility is also known, butthis compound is also poor in foaming ability and inferior inperformance as a cleanser base material.

To improve such foaming ability, JP-A-2001-181677 proposes a cleansercomposition comprising a phosphate-based surfactant having a branchedalkyl group, but is still not satisfactory.

DISCLOSURE OF INVENTION

The object of the present invention is to provide a cleanser compositionhaving a high foaming ability with a low stimulus to the skin.

The present invention provides a cleanser composition which is weaklyacidic and comprises the following components (a) and (b) in a (a)/(b)ratio of from 65/35 to 90/10 by weight:(a) a phosphate monoester represented by the general formula (1) or asalt thereof:

wherein R¹ represents an alkyl or alkenyl group containing 9 to 15carbon atoms on average with a branching degree of 10% or more, X¹ andX² each represent a hydrogen atom or an alkali metal, and n is a numberof 0 to 5 which refers to the number of ethylene oxide units added onaverage,(b) a phosphate diester represented by the general formula (2) or a saltthereof:

wherein R¹ and n each have the same meaning as defined above, and X³represents a hydrogen atom or an alkali metal.

Further, the present invention provides a cleanser composition whichfurther comprises at least one co-surfactant (referred to hereinafter ascomponent (c)) selected from the group consisting of an alkyl ethoxylatesulfate, a betaine-type surfactant, a fatty acid or a salt thereof, anamine oxide, an isethionic acid-based surfactant, a sugar-basedsurfactant, an alkanol amide, an N-acylamino acid salt and anN-acyl-N-methyl taurine salt.

Further, the present invention provides a cleanser compositionoptionally comprising a C₅₋₆ glycol as component (d), which is highlyfoaming with less increase in viscosity from ordinary temperatures tolow temperatures, thus making itself easily handled even at lowtemperatures.

Further, the present invention provides a weakly acidic cleansercomposition optionally comprising as component (e) a thickening polymercompound having a carboxyl group, which gives a freshening feeling inuse and is preferable as a cleanser for washing the body and face.

DETAILED DESCRIPTION OF THE INVENTION

In the components (a) and (b) in the present invention, R¹ is an alkylor alkenyl group containing 9 to 15 carbon atoms on average, preferably10 to 14 carbon atoms, more preferably 11 to 13 carbon atoms, and havinga branching degree of 10% or more, preferably 10 to 60%, from theviewpoint of foaming ability and water solubility.

The branching degree refers to the ratio (weight %) of branched alkylgroups or branched alkenyl groups to all alkyl groups or alkenyl groupsrepresented by R¹, and the actual branching degree is determined byanalyzing sample by gas chromatography and calculating the branchingdegree from the peak areas of the corresponding linear esters andbranched esters, as shown in the following equation:Branching degree (%)=(Σpeak areas of branched chains)/(Σpeak areas oflinear chains+Σpeak areas of branched chains)×100.

X¹, X² and X³ each represent a hydrogen atom or an alkali metal, andexamples of the alkali metal include lithium, sodium and potassium,among which sodium and potassium are preferable. n is a number of 0 to 5indicative of the number of ethylene oxide units added on average,preferably 0 to 3.

The ratio of the component (a) to the component (b) (that is, (a)/(b))in the cleanser composition of the present invention is 65/35 to 90/10,preferably 65/35 to 85/15 by weight from the viewpoint of watersolubility, foaming ability, etc. The total content of the components(a) and (b) in the cleanser composition of the present invention ispreferably 3 to 50% by weight, more preferably 5 to 35% by weight.

The components (a) and (b) in the present invention can be obtained as amixture of the components (a) and (b), for example, by reacting theircorresponding fatty alcohols with a phosphorylating agent such asphosphoric anhydride or phosphorus oxychloride under such conditionsthat the components (a) and (b) are obtained in the weight ratiodescribed above, and then neutralizing the products with an alkali suchas sodium hydroxide or potassium hydroxide. By the above reaction,phosphate triesters are also formed, but in the present invention, it ispreferable that the content of phosphate triesters in the mixture is 1%by weight or less, that is, the total content of the components (a) and(b) is 99% by weight or more.

The phosphate compound based on the components (a) and (b) has aspecific branched structure and oxyethylene groups thereby exhibiting anexcellent foaming ability without further purification.

As the fatty alcohols used, a mixture of fatty alcohols that were mixedso as to have the number of carbon atoms on average and the branchingdegree as defined above, or commercial fatty alcohols having the numberof carbon atoms on average and the branching degree as defined above,can be used.

The cleanser composition of the present invention contains thecomponents (a) and (b) in the ratio defined above, and shows weakacidity. The terms “weak acidity” refers to a pH value of 4.5 to 6.5 at25° C. upon dilution of the composition with water. In particular, thecleanser composition of the present invention is preferably the onehaving a pH value of 4.5 to 6.5 upon dilution at a concentration of 5%by weight with deionized water.

The pH value of the composition is regulated to be in the above rangewith an acid or a base, and adjusted preferably to pH 4.5 to 6.0. Theorganic acid includes, for example, citric acid, succinic acid, lacticacid, malic acid, glutamic acid, aspartic acid, pyrrolidone carboxylicacid, tartaric acid, glycolic acid, ascorbic acid, etc. The inorganicacid includes hydrochloric acid, sulfuric acid, phosphoric acid, etc.Among them phosphoric acid is particularly preferable. As the base,sodium hydroxide or potassium hydroxide are preferable.

The cleanser composition of the present invention further comprises atleast one co-surfactant as component (c) selected from the groupconsisting of an alkyl ethoxylate sulfate, a betaine-type surfactant, afatty acid or a salt thereof, an amine oxide, an isethionic acid-basedsurfactant, a sugar-based surfactant, an alkanol amide, an N-acylaminoacid salt and an N-acryl-N-methyl taurine salt. In the cleansercomposition of the present invention, the content of the component (c)is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight.

The co-surfactant as component (c) is preferably at least one memberselected from the group consisting of the following (c-1) to (c-9):(c-1) an alkyl ethoxylate sulfate represented by the general formula(3):

wherein R² represents a linear or branched alkyl or alkenyl groupcontaining 10 to 18 carbon atoms on average, X⁴ represents an alkalimetal, and m is a number of 0 to 10 indicating the number of ethyleneoxide units added on average.(c-2) a betaine-type surfactant represented by the general formula (4):

wherein R³ represents an alkyl or alkenyl group containing 8 to 18carbon atoms on average or an acyl amino alkyl group represented by theformula R⁴CONH(CH₂)_(a)— whereupon R⁴CO represents an acyl groupcontaining 8 to 18 carbon atoms on average and a is an integer of 2 to4, and X⁵ represents a —CH₂CH(OH)CH₂SO₃ ⁻ group or a —CH₂COO⁻ group.(c-3) a fatty acid or a salt thereof represented by the general formula(5):

wherein R⁵ represents a linear or branched alkyl or alkenyl groupcontaining 9 to 17 carbon atoms on average, and X⁶ represents a hydrogenatom, an alkali metal, NH₄ or alkanol ammonium.(c-4) an amine oxide represented by the general formula (6):

wherein R⁶ represents a linear or branched alkyl or alkenyl groupcontaining 8 to 18 carbon atoms on average or an acyl amino alkyl grouprepresented by the formula R⁷CONH(CH₂)_(b)— whereupon R⁷CO represents anacyl group containing 8 to 18 carbon atoms on average and b is aninteger of 2 to 4.(c-5) an isethionic acid-based surfactant represented by the generalformula (7):

wherein R⁸ represents a linear or branched alkyl or alkenyl groupcontaining 9 to 17 carbon atoms on average, and Z represents a hydrogenatom, an alkali metal, NH₄ or alkanol ammonium.(c-6) a sugar-based surfactant represented by the general formula (8):R⁹—O—(R¹⁰O)_(p)-(G)_(q)  (8)wherein R⁹ represents a alkyl or alkenyl group containing 8 to 18 carbonatoms on average, R¹⁰ represents an alkylene group containing 2 to 4carbon atoms, G represents a residue derived from a reducing sugarcontaining 5 to 6 carbon atoms, p is a number of 0 to 10 indicating thenumber of alkylene oxide units added on average, and q is a number of 1to 10 indicating the average condensation degree of the reducing sugar.(c-7) an alkanol amide represented by the general formula (9)

wherein R¹¹ represents a linear or branched alkyl or alkenyl groupcontaining 7 to 17 carbon atoms on average, R¹² represents a hydrogenatom or a methyl group, R¹³ represents a hydroxyl group or a hydrogenatom, r is a number of 1 to 5, and R¹² and R¹³, appearing in the numberof r, may be the same as or different from among themselves, providedthat at least one of (R¹³)_(r) groups is a hydroxyl group.(c-8) an N-acylamino acid salt having an acyl group containing 8 to 18carbon atoms on average,(c-9) an N-acyl-N-methyl taurine salt having an acyl group containing 8to 18 carbon atoms on average.

In the alkyl ethoxylate sulfate compound (c-1), R² is a linear orbranched alkyl or alkenyl group containing 10 to 18 carbon atoms onaverage, preferably 10 to 14 carbon atoms, more preferably 11 to 13carbon atoms, from the viewpoint of foaming ability. X⁴ represents analkali metal. Examples of the alkali metal include lithium, sodium,potassium, etc. Among them sodium and potassium are preferable. m is anumber of 0 to 10, preferably 0 to 3, indicating the number of ethyleneoxide units added on average.

In the betaine-type surfactant (c-2), R³ represents an alkyl or alkenylgroup containing 8 to 18 carbon atoms on average, preferably 10 to 14carbon atoms, or an acyl amino alkyl group represented by the formulaR⁴CONH(CH₂)_(a)— (R⁴CO represents an acyl group containing 8 to 18carbon atoms on average, preferably 10 to 14 carbon atoms, and a is aninteger of 2 to 4, preferably 3) from the viewpoint of thickeningproperties and foaming ability. R³ and R⁴CO may be a mixed alkyl groupor an alkenyl or acyl group derived from natural oils, for example,animal oils such as tallow and lard oil or vegetable oils such assoybean oil, coconut oil and palm kernel oil, or synthetic oils andmixed oils thereof. In particular, a mixed alkyl group or an acyl groupderived from coconut oil and palm kernel oil is preferable. X⁵represents a —CH₂CH(OH)CH₂SO₃ ⁻ group or a —CH₂COO⁻ group.

The betaine-type surfactant (c-2) is preferably hydroxy sulfobetainewherein R³ is an alkyl or alkenyl group containing 8 to 18 carbon atomson average, X⁵ is a —CH₂CH(OH)CH₂SO₃ ⁻ group, or amide propyl carboxybetaine wherein R³ is an acyl amino propyl group represented byR⁴CONHC₃H₆ ⁻ (R⁴CO has the same meaning as defined above) and X⁵ is a—CH₂COO⁻ group. Examples of the betaine-type surfactant include lauryldimethyl hydroxy sulfobetaine represented by formula (10), lauroyl aminopropyl dimethyl carboxy betaine represented by formula (11), coconut oilfatty acid amide propyl dimethyl carboxy betaine represented by formula(12), etc.

-   -   (R¹⁴: a group derived from coconut oil fatty acid)

In the fatty acid or its salt (c-3), R⁵ is preferably a linear orbranched alkyl or alkenyl group containing 9 to 17 carbon atoms onaverage, preferably 11 to 15 carbon atoms, more preferably 11 to 13carbon atoms, from the viewpoint of foaming ability. As the fatty acidor its salt (c-3), mixed fatty acids derived from fat and oil materialsmay be used, and examples of fats and oils include coconut oil, palmkernel oil, rapeseed oil, etc. The fatty acids derived from fats andoils may be used alone, or a combination of several kinds of fatty acidsderived from different fats and oils may be used, and when particularlya combination of fatty acids is used, the fatty acids are used desirablyin such a ratio that the average number of carbon atoms in R⁵ is in therange of 11 to 13.

X⁶ represents a hydrogen atom, an alkali metal, NH₄ or alkanol ammonium,and examples of the alkali metal include lithium, sodium, potassium,etc., and examples of an alkanol amine forming an alkanol ammonium ioninclude mono-, di- or triethanolamine, mono-, di- or tripropanolamine,etc. X⁶ is preferably sodium or potassium.

In the amine oxide (c-4), R⁶ is an alkyl or alkenyl group containing 8to 18 carbon atoms on average, preferably 10 to 14 carbon atoms, or anacyl amino alkyl group represented by R⁷CONH(CH₂)_(b)— (R⁷CO representsan acyl group containing 8 to 18 carbon atoms on average, preferably 10to 14 carbon atoms, and b is 2 to 4, preferably 3) from the viewpoint ofdetergency and foaming ability. R⁶ and R⁷CO may be a mixed alkyl groupor an alkenyl or acyl group derived from natural oils, for example,animal oils such as tallow and lard oil or vegetable oils such assoybean oil, coconut oil and palm kernel oil, or synthetic oils andmixed oils thereof. In particular, a mixed alkyl group or an acyl groupderived from coconut oil and palm kernel oil is preferable.

Preferable amine oxides include lauryl dimethyl amine oxide representedby formula (13), lauroyl amino propyl dimethyl amine oxide representedby formula (14) and coconut oil fatty acid amide propyl dimethyl amineoxide represented by formula (15).

-   -   (R¹⁵: a group derived from coconut oil fatty acid)

In the isethionic acid-based surfactant (c-5), R⁸ in the general formula(7) is preferably an alkyl or alkenyl group containing 11 to 13 carbonatoms on average. The alkali metal represented by Z includes lithium,sodium, potassium, etc., and the alkanol amine forming an alkanolammonium ion includes mono-, di- or triethanolamine, mono-, di- ortripropanolamine, etc.

Preferable examples of the isethionic acid-based surfactant (c-5)include sodium lauroyl isethionate, sodium myristoyl isethionate,potassium lauroyl isethionate, potassium myristoyl isethionate, lauroylisethionate triethanol ammonium, sodium cocoyl isethionate, potassiumcocoyl isethionate, etc.

In the sugar-based surfactant (c-6), R⁹ in the general formula (8) ispreferably an alkyl group containing 8 to 18 carbon atoms on average,particularly 10 to 14 carbon atoms (decyl group, lauryl group, myristylgroup, etc.). R¹⁰ is preferably an alkylene group containing 2 to 3carbon atoms. p is preferably 0 to 2, more preferably 0. G is a residuederived from a reducing sugar containing 5 to 6 carbon atoms, and thereducing sugar containing 5 to 6 carbon atoms is preferably glucose,galactose, fructose or the like. The average condensation degree (q) ofthe reducing sugar is 1 to 10, particularly preferably 1 to 4. q isdetermined preferably in consideration of physical properties derivedfrom the number of carbon atoms in the alkyl or alkenyl grouprepresented by R⁹; for example, when R⁹ is an alkyl or alkenyl groupcontaining 8 to 11 carbon atoms, q is preferably 1 to 1.4, and when R⁹is an alkyl or alkenyl group containing 12 to 14 carbon atoms, q ispreferably 1.5 to 4.0. q is determined by proton NMR.

In the alkanol amide (c-7), R¹¹ is a linear or branched alkyl or alkenylgroup containing 7 to 17 carbon atoms on average, preferably 10 to 14carbon atoms. R¹² is a hydrogen atom or a methyl group. R¹³ represents ahydroxyl group or a hydrogen atom, and at least one of (R¹³)_(r) groupsis a hydroxyl group. r is a number of 1 to 5, preferably 1 to 2.

Examples of the alkanol amide (c-7) include lauric acid monoethanolamide, coconut oil fatty acid monoethanol amide, palm kernel oil fattyacid monoethanol amide, lauric acid isopropanol amide, coconut oil fattyacid isopropanol amide, lauric acid glycerol amide, etc.

In the N-acylamino acid salt (C-8), the acyl group includes a saturatedor unsaturated acyl group containing 8 to 18 carbon atoms on average,preferably 10 to 14 carbon atoms, for example a single acyl group suchas octanoyl, decanoyl, lauroyl, myristoyl, palmitoyl, stearoyl oroleoyl. Preferably, the acyl group may be a mixed acyl group such ascoconut oil fatty acid acyl or palm kernel oil fatty acid acyl.

Examples of the amino acid include glutamic acid, aspartic acid,glycine, sarcosine, alanine, β-alanine, N-methyl-β-alanine, etc. Thesalt includes, but is not limited to, alkali metal salts, alkaline earthmetal salts, alkanol amine salts, etc., among which alkali metal saltssuch as sodium salts and potassium salts are preferable.

In the N-acyl-N-methyl taurine salt (C-9), the acyl group includes asaturated or unsaturated acyl group containing 8 to 18 carbon atoms onaverage, preferably 10 to 14 carbon atoms, for example, a single acylgroup such as octanoyl, decanoyl, lauroyl, myristoyl, palmitoyl,stearoyl oroleoyl. Preferably, the acyl group may be a mixed acyl groupsuch as coconut oil fatty acid acyl or palm kernel oil fatty acid acyl.The salt includes, but is not limited to, alkali metal salts, alkalineearth metal salts, alkanol amine salts, etc. Among them alkali metalsalts such as sodium salts, potassium salts, etc. are preferable.

The glycol as component (d) used in the present invention is the onecontaining 5 to 6 carbon atoms, and includes, for example, dipropyleneglycol, isoprene glycol, etc. These can be used as a mixture of two ormore thereof, and are contained in an amount of preferably 0.1 to 30% byweight, more preferably 0.5 to 15% by weight, still more preferably 1 to10% by weight, based on the whole composition.

The ratio by weight of the component (d) to the components (a) and (b),that is, (d)/((a)+(b)), is 95/5 to 5/95, preferably 80/20 to 20/80.Within this range, both foaming ability and low-temperature handling canbe maintained.

Further, the total content of the components (a), (b) and (d) is 3 to60% by weight, preferably 5 to 40% by weight. When the content is lessthan 3% by weight, the foaming ability is insufficient, while when thecontent is higher than 60% by weight, the viscosity is not stable at lowtemperatures.

As the component (e) used in the present invention, the thickeningpolymer compound having a carboxyl group is preferably the one having acarboxyl group in the molecule and having a crosslinked structure, andexamples thereof include carboxyvinyl polymers having polyacrylic acidas main chain and an allyl sucrose structure or a pentaerythritolstructure as a crosslinking group (commercial products such as Carbopol940, Carbopol 941, Carbopol 980 and Carbopol 981 manufactured by B. F.Goodrich), acrylic acid/C10-30 alkyl methacrylate copolymers (commercialproducts such as Pemulen TR1, Pemulen TR2, Carbopol 1342, and CarbopolETD2020 manufactured by B. F. Goodrich).

These can be used as a mixture of two or more thereof, and are containedin an amount of 0.005 to 5% by weight, preferably 0.1 to 2% by weight,based on the whole composition. A combination of the components (a) and(b) in the above range is preferable because the resulting cleansercomposition can achieve both a freshening feeling in use and a suitablethickening effect.

The suitable viscosity of the cleanser composition preferable as a bodyor facial cleanser at 25° C. is about 100 to 500,000 mPa·s, preferably200 to 300,000 mPa·s, still more preferably 500 to 100,000 mPa·s.

When the cleanser composition of the present invention is used as aliquid composition such as shower gel or a body shampoo, the viscositythereof at 25° C. is preferably 200 to 4000 mPa·s, particularly 500 to2000 mPa·s. When the cleanser composition of the present invention isformed into a paste such as a facial cleanser, the viscosity thereof at25° C. is preferably 10,000 to 300,000 mPa·s, particularly 20,000 to100,000 mPa·s.

The cleanser composition of the present invention does not freeze evenat low temperatures of 5° C. or less with less increase in viscosityfrom ordinary temperatures to low temperatures.

The cleanser composition of the present invention can be compounded ifnecessary with other surfactants used in conventional cleansers, forexample anionic surfactants such as alkyl benzene sulfonates, α-olefinsulfonates, alkane sulfonates, α-sulfofatty acid esters and polyoxyalkylene alkyl ether carboxylates, nonionic surfactants such as polyoxyalkylene alkyl ether and Pluronic surfactants, and cationic surfactantssuch as quaternary ammonium salts.

The cleanser composition of the present invention can be compounded ifnecessary with components used in conventional cleansers, for example,humectants such as propylene glycol, glycerine and sorbitol; viscosityregulators such as methyl cellulose, polyoxyethylene glycol distearateand ethanol; disinfectants such as triclosan and trichlorocarban;anti-inflammation agents such as potassium glycyrrhizate and acetic acidtocopherol; anti-dandruff agents such as zinc pyrithion and octopyrox;preservatives such as methylparaben, ethylparaben, propylparaben andbutylparaben; besides oils, chelating agents, perfumes, coloringmatters, feeling improvers, salts, pearlescent agents, sucrubbingagents, cooling agents, UV absorbing agents, plant extracts andantioxidants.

The cleanser composition of the present invention is suitable forwashing the skin, hair, etc. with a low stimulus to the skin and a highfoaming ability, and is useful as a facial cleanser, a shower gel, ashampoo, a body shampoo etc. Further, the cleanser composition of thepresent invention is useful as e.g. a cleanser such as a kitchencleanser brought directly into contact with the skin for a long time.

EXAMPLES Example 1

Using mixtures ab-1 to ab-3 consisting of components (a) and (b) shownin Table 1 and the component (c) shown in Table 2, cleanser compositionshaving the respective formulations shown in Tables 3 and 4 were producedin a usual manner. In the respective mixtures in Table 1, each of thecontent of trialkylphosphate was about 0.5% by weight. The pH value wasregulated by an aqueous solution of phosphoric acid or sodium hydroxide.

The pH value of the resulting composition was measured in the followingmethod to evaluate the foaming ability. The results are shown in Tables3 and 4.

<Measurement of pH>

2 g cleanser composition was weighed, 38 g deionized water was addedthereto and stirred for 5 minutes, and the pH of the uniform aqueoussolution was measured with a pH meter (HORIBA pH meter F-22) at 25° C.

<Evaluation of Foaming Ability>

The cleanser composition was diluted 10-fold with deionized water, and 4ml of the resulting aqueous solution was placed in each of 3 graduated10 ml centrifuge tubes, and the centrifuge tubes were attached side byside to a commercial handless shaker (SHK-COCK manufactured by AsahiTechno Glass Co., Ltd.). The samples were shaken at a temperature of 25°C. in a shaking cycle of 180 reciprocating motions/min. at a shakingangle of 45° for a shaking time of 15 seconds. The amounts of foams inthe respective samples were measured to give an average value of the 3samples, and judged according to the following judgment criteria:

⊚: 4.5 ml or more foams.

◯: 3.5 ml to less than 4.5 ml foams.

Δ: 2.5 ml to less than 3.5 ml foams.

X: less than 2.5 ml foams. TABLE 1 Average Average number of Branchingnumber of Weight Starting alcohol carbon degree of R¹ EO added ratio ofCounter ion (R¹—OH) atoms in R¹ (%) (n) (a)/(b) X¹ X² X³ ab-1 Dobanol23*¹ 12.5 25 0 80/20 K H K ab-2 2 75/25 Na H Na ab-3 2 60/40 Na H Na*¹a product of Mitsubishi Chemical Co., Ltd.

TABLE 2 c-1-1 Lauryl ethoxylate (2) sulfate (in formula(3), R² = laurylgroup, m = 2, X⁴ = Na) c-2-1 Lauryl dimethyl hydroxy sulfobetaine(compound represented by formula (10)) c-2-2 Lauroyl amino propylcarboxy betaine (compound represented by formula (11)) c-2-3 Coco-amidepropyl carboxy betaine (compound represented by formula (12)) c-3-1Sodium laurate c-4-1 Lauryl dimethyl amine oxide c-5-1 Sodium lauroylisethionate c-5-2 sodium coco-acyl isethionate c-6-1 Decyl glucosidec-7-1 Lauric acid monoethanol amide c-8-1 Sodium lauroyl glutamate c-9-1Lauroyl-N-methyl taurine sodium salt

TABLE 3 products of the present invention 1 2 3 4 5 6 7 8 9 10 11 12 1314 Cleanser Mixture of ab-1 15 20 composition component ab-2 20 15 15 1515 15 15 15 15 15 15 15 (weight %) (a) and ab-3 component (b) componentc-1-1 5 5 (c) c-2-1 5 c-2-2 5 c-2-3 5 c-3-1 5 c-4-1 5 c-5-1 5 c-6-1 5c-7-1 5 c-8-1 5 c-9-1 5 pH regulating agent(aqueous Suitable amountsolution of phosphoric acid or sodium hydroxide) Deionized water Balance(amount for adjustment to 100% by weight in total) Evaluation result pH5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.05 5.5 5.5 5.5 5.5 Foaming ability◯ ◯ ◯ ◯ ⊚ ◯ ⊚ ◯ ◯ ⊚ ⊚ ◯ ◯ ◯

TABLE 4 Comparative product 1 2 3 4 5 6 7 8 9 10 11 12 13 CleanserMixture of ab-1 15 composition component(a) ab-2 15 15 15 15 15 15 15 1515 15 15 (weight %) and component ab-3 15 (b) Component c-1-1 5 5 5 (c)c-2-1 5 c-2-2 5 c-2-3 5 c-3-1 5 c-4-1 5 c-5-1 5 c-6-1 5 c-7-1 5 c-8-1 5c-9-1 5 pH regulating agent(aqueous Suitable amount solution ofphosphoric acid or sodium hydroxide) Deionized water Balance (amount foradjustment to 100% by weight in total) Result of pH 5.5 7.0 7.0 7.0 7.07.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 evaluation Foaming ability Δ Δ Δ Δ Δ Δ ΔX Δ Δ X Δ Δ

Example 2

Using a phosphate mixture shown in Table 5, a cleanser compositionhaving a formulation shown in Table 6 was produced in a usual manner.The resulting cleanser composition was evaluated for its viscosity at 0°C. and 25° C. and for its foaming ability at 40° C. Assuming use of thecleanser composition in washing of the face and body with warm water,the foaming ability was evaluated at 40° C. The results are showncollectively in Table 6.

(Evaluation Method)

(1) Viscosity

Each cleanser composition was stored at each temperature of 0° C. and25° C. for 24 hours, and the viscosity at each temperature was measuredwith a BM type viscometer (TOKIMEC INC.).

(2) Foaming Ability

Each cleanser composition was diluted 10-fold with deionized water, and2 g lanoline was added as artificial dirt to 100 ml of the resultingaqueous solution, then introduced into a graduated glass cylinder havingan inner diameter of 6.5 cm, and stirred at 40° C. at 1000 rpm for 1minute by contrarotation at 10-second intervals with a flat propeller.Five minutes after stirring was finished, the amount of foams generatedwas measured and judged according to the following criteria:

◯: 155 ml or more foams.

Δ: 145 ml to less than 155 ml foams.

X: less than 145 ml foams. TABLE 5 Average Avereage Branching number ofnumber of degree of moles of EO weight Starting alcohol carbon R¹ addedratio of Counter ion Phosphate (R¹—OH) atoms in R¹ (%) (n) (a)/(b) X¹ X²X³ ab-4 Diadol 11*¹ 11.0 50 0 80/20 K H K ab-3 Dobanol 23*¹ 12.5 25 260/40 Na H Na ab-2 Dobanol 23*¹ 12.5 25 2 75/25 Na H Na ab-5 Dobanol23*¹ 12.5 25 2 95/5  Na H Na ab-6 Kalcol 2098*¹ 12.0 0 2 75/25 Na H Na*¹product of Mitsubishi Chemical Co., Ltd.*²product of Kao corporation

TABLE 6 Products of the present invention Comparative productComponent(weight %) 1 2 3 4 1 2 3 4 5 6 7 8 9 A · B Phosphate(ab-4) 3030 30 30 Phosphate(ab-3) 30 30 Phosphate(ab-2) 30 30 30 Phosphate(ab-5)30 30 Phosphate(ab-6) 30 30 C Dipropylene glycol 5 5 5 5 5 Isopreneglycol 5 5 1,3-Butanediol 5 Deionized water Balance Viscosity(mPa · s):0° C. 606 590 1260 1110 2530 3180 2060 778 3240 2600 5160 5800 5880Viscosity(mPa · s): 25° C. 292 230 718 690 254 908 996 202 366 870 12201180 334 Foaming ability ◯ ◯ ◯ ◯ Δ X X X Δ X X X X

Example 3 Facial Cleanser

A facial cleanser in a paste form having the formulation shown below wasproduced in a usual manner.

The resulting facial cleanser had a high foaming ability and a viscosityof 45,000 mPa·s at 25° C. and a viscosity of 48,000 mPa·s at 0° C. withless increase in viscosity at low temperatures. (Components) Phosphatemixture (ab-2) 20 (weight %) Lauryl phosphoric acid 5 Lauryl hydroxysulfobetaine (c-2-1) 3 Lauric acid 2 Dipropylene glycol 3 Ethyleneglycol distearate 1.5 Dibutyl hydroxy toluene 0.02 EDTA · 4H₂O 0.02Sodium chloride 3 Perfume 0.5 48% Sodium hydroxide amount for adjustmentto pH 5.5 Water balance

Example 4

Using a phosphate mixture shown in Table 5, a cleanser compositionhaving a formulation shown in Table 7 was produced in a usual manner.The resulting cleanser composition was evaluated for rinsing andviscosity. The results are shown collectively in Table 7.

(Evaluation Method)

(1) Rinsing

An evaluation panel of 10 men and 10 women took 5 g of each cleansercomposition on one hand, diluted it with tap water, and washed bothbands, and easiness of rinsing was evaluated according to the followingcriteria and judged in terms of average score.

<Evaluation Criteria>

Score 0: Hardly rinsed.

Score 1: Slightly hardly rinsed.

Score 2: Easily rinsed.

Score 3: Very easily rinsed.

<Judgment Criteria>

◯: An average score of 2 to 3.

Δ: An average score of 1 to less than 2.

X: An average score of 0 to less than 1.

(2) Viscosity

The viscosity of each cleanser composition at 25° C. was measured with aBM type viscometer (TOKIMEC INC.). TABLE 7 Comparative Present inventionproduct Component(weight-%) 1 2 3 4 5 6 1 2 AB Phosphate(ab-4) 15 15 15Phosphate(ab-3) Phosphate(ab-2) 15 15 15 Phosphate(ab-5) 15 15Phosphate(ab-6) C Carbopol 940 1.0 1.0 Carbopol ETD2020 1.0 1.0 1.0Pemulen TR1 1.0 1.0 1.0 Malic acid Amount for adjustment topredetermined pH Deionized water Balance pH 5.6 5.4 5.5 5.4 5.5 5.5 5.55.5 Rinsing ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Viscosity (mPa · s) 6090 5930 3600 6680 70303970 5500 2060 Comparative product Component(weight-%) 3 4 5 6 7 8 9 1011 AB Phosphate(ab-4) 15 Phosphate(ab-3) 15 15 15 Phosphate(ab-2) 15Phosphate(ab-5) 15 Phosphate(ab-6) 15 15 15 C Carbopol 940 CarbopolETD2020 1.0 1.0 Pemulen TR1 1.0 1.0 Malic acid Amount for adjustment topredetermined pH Deionized water Balance pH 5.5 5.6 5.5 5.4 5.5 5.5 5.45.5 5.5 Rinsing Δ Δ Δ Δ Δ X Δ Δ Δ Viscosity (mPa · s) 3610 2220 40603130 39.2 39.0 80.6 62.8 44.2

Example 5 Body Shampoo

A body shampoo having the formulation shown below was produced in ausual manner.

The resulting body shampoo had a viscosity of 3, 100 mPa·s at 25° C. andcould be easily rinsed to give a freshening feeling in use. (Components)Phosphate mixture (ab-2) 15 (weight %) Pemulen TR1 0.2 Sodium laurylether sulfate 3 Lauryl hydroxy sulfobetaine (c-2-1) 3 Lauric acid 1Glycerine 10 Ethylene glycol distearate 2 Dibutyl hydroxy toluene 0.02EDTA · 4H₂O 0.02 85% Phosphoric acid amount for adjustment to pH 5.5Perfume 0.8 Water balance

Example 6 Facial Cleanser

A facial cleanser in a paste form having the formulation shown below wasproduced in a usual manner.

The resulting facial cleanser had a viscosity of 83,000 mPa·s at 25° C.and could be easily rinsed to give a freshening feeling in use.(Components) Phosphate mixture (ab-2) 15 (weight %) Carbopol ETD2020 0.6Laurylphoshoric acid 5 Lauryl hydroxy sulfobetaine (c-2-1) 5 Lauric acid1 Glycerine 10 Ethylene glycol distearate 1.5 Dibutyl hydroxy toluene0.02 EDTA · 4H₂O 0.02 85% Phosphoric acid amount for adjustment to pH5.5 Perfume 0.8 Water balance

Example 7

Cleanser compositions were prepared using ab-2 shown in Table 1 andcomponent (c) of a co-surfactant shown in Table 2 according to theformulations shown in Table 8. They were tested in the same way as shownin Example 1. Results of foaming ability (ml) are shown in Table 8. Itis noted that the composition obtained by combining the phosphatemixture of the invention with a co-surfactant is significantly improvedin view of foaming ability. TABLE 8 Present invention 41 42 43 44 45 4647 48 49 50 51 52 53 54 55 56 Mixture of ab-2 1.6 1.6 1.6 1.6 1.6 2.02.0 4.0 4.0 4.0 6.0 6.0 7.0 7.0 9.0 9.0 component(a) + component(b)Component (c) c-1-1 0.4 c-2-1 0.4 c-2-2 2.0 c-3-1 0.4 c-4-1 0.4 c-5-20.4 c-6-1 2.0 c-7-1 2.0 c-8-1 2.0 c-9-1 2.0 pH adjuster Proper amountDeionized water Balance pH 5.5 5.5 5.5 5.5 5.5 5.5 7.0 5.5 5.5 5.5 5.57.0 5.0 5.0 5.5 7.0 Amount of foams 3.7 4.5 5.7 4.7 4.9 3.8 3.5 4.5 4.34.8 3.6 3.5 4.4 4.5 3.8 3.7 (ml)

Example 8 Facial Cleanser

A facial cleanser formulation in a paste form is shown below.(Components) Phosphate mixture (ab-2) 15 (weight %) Carbopol ETD2020 0.6Lauroylaminopropyl carbobetaine 5 (c-2-2) Sorbitol 14 Dibutyl hydroxytoluene 0.02 EDTA ·4H₂O 0.02 85% Phosphoric acid amount for adjustmentto pH 5.5 Perfume 0.4 Water balance

1. A cleanser composition which is weakly acidic and comprises thefollowing components (a) and (b) in a (a)/(b) ratio of from 65/35 to90/10 by weight: (a) a phosphate monoester represented by the generalformula (1) or a salt thereof:

wherein R¹ represents an alkyl or alkenyl group comprising 9 to 15carbon atoms on average with a branching degree of 10% or more, X¹ andX² each represent a hydrogen atom or an alkali metal, and n is a numberof 0 to 5 which refers to the number of ethylene oxide units added onaverage, (b) a phosphate diester represented by the general formula (2)or a salt thereof:

wherein R¹ and n each have the same meaning as defined above, and X³represents a hydrogen atom or an alkali metal.
 2. The cleansercomposition according to claim 1, which exhibits a pH value of 4.5 to6.5 upon dilution at a concentration of 5% by weight with deionizedwater.
 3. The cleanser composition according to claim 1, wherein thetotal amount of the components (a) and (b) is 3 to 50% by weight.
 4. Thecleanser composition according to claim 1, which further comprises atleast one co-surfactant, referred to hereinafter as component (c),selected from the group consisting of an alkyl ethoxylate sulfate, abetaine-type surfactant, a fatty acid or a salt thereof, an amine oxide,an isethionic acid-based surfactant, a sugar-based surfactant, analkanol amide, an N-acylamino acid salt and an N-acyl-N-methyl taurinesalt.
 5. The cleanser composition according to claim 4, which furthercomprises, as said component (c), at least one member selected from thegroup consisting of: (c-1) an alkyl ethoxylate sulfate represented bythe general formula (3):

wherein R² represents a linear or branched alkyl or alkenyl groupcomprising 10 to 18 carbon atoms on average, X⁴ represents an alkalimetal, and m is a number of 0 to 10 indicating the number of ethyleneoxide units added on average; (c-2) a betaine-type surfactantrepresented by the general formula (4):

wherein R³ represents an alkyl or alkenyl group comprising 8 to 18carbon atoms on average or an acyl amino alkyl group represented by theformula R⁴CONH(CH₂)_(a)— whereupon R⁴CO represents an acyl groupcomprising 8 to 18 carbon atoms on average and a is an integer of 2 to4, and X⁵ represents a —CH₂CH(OH)CH₂SO₃ ⁻ group or a —CH₂COO⁻ group;(c-3) a fatty acid or a salt thereof represented by the general formula(5):

wherein R⁵ represents a linear or branched alkyl or alkenyl groupcomprising 9 to 17 carbon atoms on average, and X⁶ represents a hydrogenatom, an alkali metal, NH₄ or alkanol ammonium; (c-4) an amine oxiderepresented by the general formula (6):

wherein R⁶ represents a linear or branched alkyl or alkenyl groupcomprising 8 to 18 carbon atoms on average or an acyl amino alkyl grouprepresented by the formula R⁷CONH(CH₂)_(b)— whereupon R⁷CO represents anacyl group comprising 8 to 18 carbon atoms on average and b is aninteger of 2 to 4; (c-5) an isethionic acid-based surfactant representedby the general formula (7):

wherein R⁸ represents a linear or branched alkyl or alkenyl groupcomprising 9 to 17 carbon atoms on average, and Z represents a hydrogenatom, an alkali metal, NH₄ or alkanol ammonium; (c-6) a sugar-basedsurfactant represented by the general formula (8):R⁹—O—(R¹⁰O)_(p)-(G)_(q)  (8) wherein R⁹ represents a linear or branchedalkyl or alkenyl group comprising 8 to 18 carbon atoms on average, R¹⁰represents an alkylene group comprising 2 to 4 carbon atoms, Grepresents a residue derived from a reducing sugar comprising 5 to 6carbon atoms, p is a number of 0 to 10 indicating the number of alkyleneoxide units added on average, and q is a number of 1 to 10 indicatingthe average condensation degree of the reducing sugar; (c-7) an alkanolamide represented by the general formula (9):

wherein R¹¹ represents a linear or branched alkyl or alkenyl groupcomprising 7 to 17 carbon atoms on average, R¹² represents a hydrogenatom or a methyl group, R¹³ represents a hydroxyl group or a hydrogenatom, r is a number of 1 to 5, and (R¹²)_(r) groups and (R¹³)_(r) groupsmay be the same or different, respectively, provided that one of(R¹³)_(r) groups is a hydroxyl group; (c-8) an N-acylamino acid salthaving an acyl group comprising 8 to 18 carbon atoms on average, and(c-9) an N-acyl-N-methyl taurine salt comprising an acyl groupcomprising 8 to 18 carbon atoms on average.
 6. The cleanser compositionaccording to claim 4, wherein the content of the component (c) is 0.5 to20% by weight.
 7. The cleanser composition according to claim 2, whereinthe total amount of the components (a) and (b) is 3 to 50% by weight. 8.The cleanser composition according to claim 5, wherein the content ofthe component (c) is 0.5 to 20% by weight.